As conceptualized by otto kernberg (1928–), a primitive character structure represented by a fluid and labile sense of identity; desperate fear of isolation and aloneness, along with chaotic intimate relationships in which the other is both intensely needed and experienced as toxic and rejecting; and the use of archaic defenses of splitting and projective identification. Individuals with this personality organization often manifest eruptive anger in chaotic relationships, yet in nonintimate situations, they often function well.